Surface acoustic wave convolver with two output electrodes of different lengths

Claim 1

A surface acoustic wave convolver comprising: a piezoelectric substrate; plural input transducers formed on said substrate and adapted for respectively generating surface acoustic waves corresponding to input signals; and an output transducer for obtaining a convolution signal of said input signals from a surface acoustic wave generated by non-linear interaction of the surface acoustic waves generated by said input transducers; wherein said output transducer is formed by first and second output electrodes provided in parallel manner between said input transducers and having mutually different lengths along the propagating direction of said surface acoustic wave; and wherein the difference ΔL in length of said first and second output electrodes substantially satisfies following condition: ΔL·(1/v.sub.m -1/v.sub.o)=(n+1/2)·1/f wherein V m is the velocity of the surface acoustic wave on the substrate surface covered with said output electrode, V 0 is the velocity of the surface acoustic wave on the free surface of the substrate not covered by said output electrode, f is the center frequency of said input signals, and n is an integer.